Answer:
6.0 cm²
Step-by-step explanation:
You want the area of ∆DEF with sides e=1.4 cm, f=9.1 cm, and angle D=109°.
Area
The area of the triangle is given by the formula ...
A = 1/2ef·sin(D)
A = 1/2(1.4 cm)(9.1 cm)sin(109°) ≈ 6.37·0.94552 cm² ≈ 6.023 cm²
The area of triangle DEF is about 6.0 square centimeters.
